JPH0445061Y2 - - Google Patents

Description

[Detailed description of the invention] [Industrial field of application] The present invention is attached to the front side of a display device,
The present invention relates to a photo-detection type coordinate input device that detects a coordinate position relative to a display surface of a display device and inputs it to a computer, and particularly relates to a coordinate input device that takes measures to prevent malfunction.

[Conventional technology]

Among coordinate input devices that are manually entered into a computer, optical detection type devices that allow coordinates to be identified by simply pressing a desired point on the front of the display device with a finger or the like are attracting attention due to their reliability and operability. There is.

Conventionally, as this kind of optical detection type coordinate input device, those shown in FIGS. 3 to 5 are known. Here, FIG. 3 is a perspective view showing an example in which the coordinate input device is attached to the front surface of the display device, FIG. 4 is a sectional view of the main part on the light receiving element side, and FIG. FIG.

This coordinate input device has a frame 1 formed into a substantially rectangular shape and having an opening 2 in the center, and a rear side of the frame 1, that is, a display surface 3a side of a display device 3 using a CRT or the like, facing each other. A plurality of pairs of light-emitting elements 4 such as LEDs and light-receiving elements 5 such as phototransistors are arranged on each side, and a position where the optical path 11 is blocked is determined from among the combinations of these light-emitting elements 4 and light-receiving elements 5. It mainly consists of an arithmetic unit 6 that detects the coordinate position and inputs the coordinate position to the host computer side. Note that the light emitting element 4 and the light receiving element 5 are the former light emitting part 4a and the latter light receiving part 5.
Terminals of these optical semiconductor elements 4 and 5 are soldered to a substrate 7 attached to the frame 1 so that the terminals of the optical semiconductor elements 4 and 5 face each other in pairs.

The opening 2 is equipped with a VDT (Video Display).
An operation panel 10 consisting of a terminal (terminal) filter is provided to make the display surface 3a of the display device 3 easy to view and to prevent dirt and dust from adhering to the display surface 3a. Further, on the front surface of the row-shaped light receiving elements 5, a light transmitting hole 8 having a predetermined area and depth is provided so that only the incident light from the light emitting element 4 serving as a pair can be received.
A light shielding plate 8 on which a is formed is provided. Further, on the front surface of the light shielding plate 8 and the front surface of the light receiving element 4, a rectangular frame-shaped infrared filter 9 is attached over the entire circumference as a visible light exclusion filter.
In other words, a row of light receiving elements 5 arranged in a substantially L-shape.
The front surface of the light emitting element 4 and the front surface of the light emitting element 4, which is also arranged in a substantially L-shape, respectively face each outer wall surface of the rectangular frame-shaped infrared filter 9. Therefore, an invisible optical path 11 is formed through the infrared filter 9 on the front surface of the operation panel 10, that is, on the side not facing the display surface 3a.

When detecting the coordinate position, for example, the third and fifth
As shown in the figure, when you press the position on the display surface 3a where you want to input with your finger 12 from above the operation panel 10, an optical path 11 is formed along the surface of the operation panel 10.
Since the part of the light that should pass through the finger 12 is blocked there, by sequentially causing the light emitting elements 4 to emit light and scanning, the blocked optical path 11 is directed to the light receiving element 5 in each of the x and y directions. It can then be detected. This shielded optical path 11 is specified by the arithmetic unit 6, and its coordinate position is output to a host computer (not shown).

By the way, in the case of such a coordinate input device using the photo-detection method, the light emitted from the light emitting portion 4a of the light emitting element 4 located near the corner of the opening portion 2 off the predetermined optical path 11 passes through the infrared filter 9. There is a possibility that the light may be reflected at approximately the center in the longitudinal direction of the inner wall surface of the opening 2, or may propagate inside the infrared filter 9 and reach the light receiving portion 5a of the corresponding light receiving element 5. Even if the user presses the vicinity of the corner with the finger 12, there is a risk that the interruption of the optical path 11 will not be detected and malfunction will occur.

Therefore, conventionally, as shown in FIG.
Alternatively, a recess 9b may be provided in a part of the outer wall surface of the infrared filter 9 to prevent the light from the light emitting part 4a entering there from being reflected toward the light receiving part 5a. A device has been proposed that is intended to prevent the light propagating inside from reaching the light receiving section 5a.

[Problem that the invention attempts to solve]

However, in reality, in addition to this, the light emitting part 4a
There is also a risk that the light emitted from the infrared filter 9 and transmitted through the infrared filter 9 may be reflected at the approximate center in the longitudinal direction of the substrate 7 or the light shielding plate 8 located on the back side of the filter 9 and reach the light receiving section 5a. However, the above-mentioned conventional proposals could hardly be said to be sufficient as measures to prevent malfunctions (see Fig. 6). Further, as shown in FIGS. 7 and 8, a light-shielding holder 13, which is a combination of an upper mold 14 and a lower mold 15 and is capable of storing light-receiving elements 5 in a row, is connected to a substrate 7 and an infrared filter 9.
In the case of a coordinate input device disposed between the two, the front surface of the light-shielding holder 13 at approximately the center in the longitudinal direction,
There is a risk that the light from the light emitting section 4a may be reflected toward the light receiving section 5a, so measures should be taken in consideration of light reflection from members located on the back side of the infrared filter 9. However, it has become necessary to improve the reliability of coordinate input devices.

Therefore, the purpose of the present invention is to prevent the member disposed on the back side of a visible light exclusion filter such as an infrared filter that defines the periphery of the opening from causing undesired light reflection that may cause malfunction. An object of the present invention is to provide a coordinate input device that is safe and highly reliable.

[Means for solving problems]

In order to achieve the above object, the present invention has a member disposed at a predetermined interval opposite the surface of the visible light exclusion filter that defines the periphery of the opening and is opposite to the opening side; At a position equidistant from the light emitting element and the corresponding light receiving element on the surface of the member on the side of the visible light exclusion filter, the light that has deviated from the light emitting element and passed through the visible light exclusion filter is displayed. A structure is adopted in which reflection prevention means outside the filter is provided to prevent reflection toward the light receiving element.

[Effect]

That is, according to the present invention, a convex shape is formed at a predetermined position of a member such as a substrate, a light shielding plate, or a light shielding holder disposed on the back side of the visible light exclusion filter, that is, at a position where there is a risk of causing undesired light reflection. Since the filter is equipped with a means to prevent reflections on the body, recesses, paint, etc., the light that enters the relevant position from the light emitting element is
The light is diffusely reflected or absorbed by the outside reflection prevention means of the filter, and is prevented from being reflected toward the light receiving element.

〔Example〕

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is a front view of essential parts showing one embodiment of a coordinate input device according to the present invention, and parts corresponding to those in FIGS. 3 to 6 are given the same reference numerals.

In FIG. 1, a rectangular frame-shaped infrared filter 9 disposed as a visible light exclusion filter at a position defining the periphery of the opening 2 is connected to the light emitting portion 4a of the light emitting element 4 or the light shielding plate on each side. 8 light transmission holes 8
It faces the light receiving section 5a of the light receiving element 5 via the infrared filter 9, and an invisible optical path 11 is formed between the light emitting section 4a and the light receiving section 5a via the infrared filter 9. Approximately at the center in the longitudinal direction of each side of the infrared filter 9, there is a convex portion 9a on the inner wall surface side.
However, concave portions 9b are provided on the outer wall surface side, and the convex portions 9a allow the light path 11 from the light emitting portion 4a.
This prevents the occurrence of an undesirable situation in which light emitted from the infrared filter 9 is reflected by the inner wall surface of the infrared filter 9 and reaches the light receiving section 5a, and
The concave portion 9b also prevents the occurrence of an undesirable situation in which light that has deviated from the optical path 11 from the light emitting portion 4a and enters the infrared filter 9 propagates within the filter 9 and reaches the light receiving portion 5a. ing.
In other words, the convex portions 9a and the concave portions 9b take measures to prevent malfunctions caused by reflection and propagation of light from the infrared filter 9 extending parallel to the optical path 11.

Further, at approximately the center in the longitudinal direction of the substrate 7 disposed on the back side of the infrared filter 9 and extending parallel to the optical path 11, a convex body 7a is erected toward the recess 9b as means for preventing reflection outside the filter. This convex body 7a prevents an undesirable situation in which light that has deviated from the optical path 11 from the light emitting section 4a and is incident on the substrate 7 is reflected on the surface of the substrate 7 and reaches the light receiving section 5a. Occurrence has been prevented. That is, if the convex body 7a does not exist, the light emitted from the light emitting part 4a, transmitted through the infrared filter 9, and incident on the substantially central part in the longitudinal direction of the substrate 7 is reflected there, and transmitted through the infrared filter 9 again. However, if the convex body 7a is provided at a predetermined position, such undesired reflection will not occur, and light reflection from the member on the back side of the infrared filter 9 will occur. It is also possible to eliminate malfunction factors that have not been considered in the past, and more reliable malfunction prevention measures can be implemented.

Although the above embodiment has described the anti-reflection means outside the filter in the light-emitting element array, the light-receiving element array also includes a convex body (not shown) approximately in the longitudinal center of the light-shielding plate 8 located on the back side of the infrared filter 9. is provided. In addition, these convex bodies provided approximately in the longitudinal center of the substrate 7 and the light shielding plate 8 are the light emitting portions 4a
The shape is not particularly limited as long as it does not reflect the light toward the light receiving part 5a.For example, instead of the convex body 7a, a
Mounting components such as ICs may also be arranged. Furthermore, the same effect can be obtained by providing a recess at the corresponding position of the substrate 7 or the light shielding plate 8 in order to diffusely reflect the light from the light emitting part 4a, or by applying a highly light-absorbing paint. Is possible.

FIG. 2 is a front view of the essential parts of another embodiment of the present invention, in which the same malfunction prevention measures as in the previous embodiment have been taken for a coordinate input device employing a light-shielding holder. This light-shielding holder 13 is shown in FIG.
As shown in FIG. 8, a plurality of light-receiving elements 5 are arranged in a row between the substrate 7 and the infrared filter 9, and in the case of this embodiment, the light-receiving elements 5 are removed from the light path 11 from the light-emitting part 4a. In order to prevent the incident light from being reflected on the front surface of the light-shielding holder 13 and heading toward the corresponding light-receiving section 5a, a recess 13a is provided as a means for preventing reflection outside the filter at approximately the center in the longitudinal direction of the front surface of the light-shielding holder 13. is provided.

[Effect of idea]

As explained above, according to the present invention, for members such as a substrate, a light-shielding plate, or a light-shielding holder disposed on the back side of a visible light exclusion filter, the back side of these members is removed from a predetermined optical path from a light emitting element. Since a reflection prevention means outside the filter is provided to prevent the incident light from being reflected toward the light receiving element, it is possible to eliminate malfunction factors that have not been considered in the past, and to prevent malfunction of the coordinate input device. Reliability can be improved.

[Brief explanation of the drawing]

FIG. 1 is a front view of main parts showing one embodiment of the coordinate input device according to the present invention, FIG. 2 is a front view of main parts showing another embodiment of the coordinate input device according to the present invention, and FIGS. Figure 5 is for explaining an example of a conventional coordinate input device, Figure 3 is a perspective view showing the coordinate input device attached to the front of the display screen, and Figure 4 is a main part on the light receiving element side. Cross-sectional view, Figure 5 is a back view showing the internal structure of the coordinate input device, Figure 6 is a front view of the main part showing a conventional proposal that takes measures to prevent malfunctions in the infrared filter, and Figure 7 is a coordinate system using a light-shielding holder. FIG. 8 is a sectional view of a main part of the input device on the light-receiving element side, and a perspective view showing the internal shape of the light-shielding holder. 2... Opening portion, 3... Display device, 3a... Display surface, 4... Light emitting element, 5... Light receiving element, 7... Substrate, 7a... Convex body, 8... Light shielding plate, 9... ...Infrared filter (visible light exclusion filter), 11... Optical path, 13... Light-shielding holder, 13a... Recess.

Claims (1)

[Claims for Utility Model Registration] (1) A light emitting device consisting of a frame with a substantially rectangular opening formed in the center and a plurality of light emitting elements arranged in parallel along two sides of the opening of the frame. an element array, a light-receiving element array consisting of a plurality of light-receiving elements arranged in parallel on two sides facing the element array, and a visible light array that defines a periphery of the opening and is provided facing the light-emitting element and the light-receiving element. a visible light exclusion filter, forming an optical path between the light emitting element and the corresponding light receiving element on the front side of the display surface of the display device through the visible light exclusion filter, and detecting a position where this optical path is blocked. In a photo-detection type coordinate input device for inputting coordinate positions on a display surface using a photodetection method, a member is provided at a predetermined distance from a surface opposite to the opening side of the visible light exclusion filter. at a position equidistant from the light emitting element and the corresponding light receiving element on the surface of the member on the side of the visible light exclusion filter, and passing through the visible light exclusion filter off a predetermined optical path from the light emitting element. What is claimed is: 1. A coordinate input device comprising an external reflection prevention means for preventing the reflected light from being reflected in the direction of the light receiving element. (2) The coordinate input device as set forth in claim (1) of the utility model registration, characterized in that a convex body is provided at the position of the member as the reflection prevention means outside the filter. (3) The coordinate input device as set forth in claim (1) of the utility model registration, characterized in that a concave body is provided at the relevant position of the member as the reflection prevention means outside the filter. (4) The coordinate input device as set forth in claim (1) of the utility model registration, characterized in that, as the filter external reflection prevention means, a paint with high light absorption is applied to the relevant position of the member. .